Electronic keyboards (sometimes referred to as music synthesizers) utilize electro-mechanical devices to output electrical signals as a result of actuation of keys on the keyboard to synthesize audible music that replicates the sound of, for example, a piano. In many electronic keyboards, a user moves the keys with his fingers, and the keys actuate switches which open/close a circuit to indicate to a central processor what note is desired to be synthesized. Typically, a device, such as a helical spring, is used to provide a mechanism to return a given key to its rest position, and to provide sufficient resistance against movement to provide a quasi-artificial feel akin to a traditional piano key.
Helical springs have a spring constant such that the force of the spring working against the movement of the key varies as the key moves. For example, if the helical spring is compressed/extended by ten percent of its total at-rest length as a result of movement of the key downward, the force imparted by the spring on the key may be, for example, a tenth of a pound. However, if that same spring is compressed/extended to a distance of 15 percent of its at-rest length, the outputted force of the spring may be 0.15 pounds. That is, the resistance of the key increases as the user presses the key further downward, thus forcing the user to increase the force that he or she applies on the key as the user presses the key to its fully depressed position. This results in an awkward feel for the user, and also may result in the user applying extra force at the beginning of the movement of the key to compensate for the expected greater force that will be necessary to move the key all the way down towards its fully depressed position. This results in a skilled user not being able to fully exercise his or her musical talents on an electronic keyboard.